Method of burning oil



Bea, 3, 1935. J. J, HARMAN 2,023,074

METHOD OF BURNING OIL Original Filed Oct. 12, 1931 4 Sheets-Sheet l IN VE N TOR J57z72 Jf'fldr'maiz Q W MMTTORNEY.

Dec. 3, 1935. J. .1. HARMAN METHOD OF BURNING OIL Original Filed 06. 12, 1951 4 Sheets-Sheet 2 IN VENTOR Jfirz ffiarmavz W TTORNEY.

I! IIIIII I] Dec. 3, 1935. J. J, HARMAN METHOD OF BURNING OIL Original Filed Oct. 12, 1931 4 Sheets-Sheet 3 INVENTOR. 1070/2 Jflarma'rz A TTORNEY.

Dec. 3, 1935.. J. .1. HARMAN 2,023,074

METHOD OF BURNING 61L Original Filed Oct. 12, 1951 4 Sheets-Sheet 4 ATTORNEY.

Patented Dec. 3, 1935 UNITED STATES PATENT OFFICE NIETHOD 0F BURNING OIL Original application October 12, 1931, Serial No.

2 Claims.

This invention relates to methods of burning liquid fuel and more particularly with domestic burners of the steam atomizing type.

One object of the invention is to insure that adequate heat to maintain a desired house temperature will be available at all times.

Another object of the invention is to regulate the operation of the burner automatically in response to the heat requirements.

Another object of the invention is to utilize the least amount of fuel commensurate with efficient combustion.

Another object of the invention is to subdue combustion noise.

Other objects of the invention will become apparent from the following description taken in connection with the accompanying drawings, wherein:-

Fig. 1 is a side elevation of an oil burner adapted to carry out the method disclosed herein.

Fig. 2 is a plan view of the same.

Fig. 3 is a front elevation, partly in section, taken on the line of 3-3 of Fig. 1, looking in the direction indicated by the arrows.

Fig. 4 is a section taken on the line of 44 of Fig. 2 looking in the direction indicated by the arrows, and

Fig. 5 is a section taken on the line of 5-5 of Fig. 1 looking in the direction indicated by the arrows.

This application is a division of my copending application Serial No. 568,285, filed October 12-, 1931. It will be understood that the invention is not limited in its application to the specific type of burner to be described since burners of different construction may be adapted to operate in like manner once the principle is understood.

Referring more particularly tothe drawings, the oil burner is shown therein as comprising a plurality of units such as the base plate A, the water feeder B, the ignition chamber C, the nozzle housing D, the combustion chamber E, the steam generator F, and the safety trip valve unit G for the fuel line.

The base plate A is preferably of sheet metal and, in contour, conforms in general to the shape of the units it supports. The base plate may be secured to the floor by means of the leg ID as shown in Fig. 1.

The water feeder B (Figs. 1, 2 and 3) which is the subject matter of an independent and copending application, is mounted on the plate A at the front end thereof and consists of a cup shaped body l5 having its open end closed by a cover it. A lead gasket 31' may be interposed Divided and this application July 29, 1933, Serial No. 682,809

Formed integrally with the feeder body t5 adjacent. upper end is a lateral hollow projection ll carrying a valve body 23. The valve body 23 is provided witha valve seat 25 with which a valve member 26 cooperates to control the .flow of fluid throughan aperture 21 in the seat. The valve member 26 is provided. with a stem 28 having spaced webs 29 thereon engaging the interior of the valve body 23' for positioning the valve therein Water is conveyed to the valve from a suitable source of supply by means of the pipe 20 connected to the valve body 23' by means of the union 2t and nut 24'. Preferably a filter plate 22 is interposed between the valve body 23 and the union 2 t, as shown Fig. 3. In order to maintain a desired quantity of water in the feeder the valve stem. 28 connected to a lever arm 32 pivoted on a pin 33 and carrying a float 34 positioned in the body 15 of the feeder.

On the opposite side of the body l5 from the valve is a threaded boss 35 which carries a pipe 62 connected at its opposite end to the steam chamber of steamv generator F; In this manner steam is conveyed into the water feeder B for equalizing the pressure between feeder B and generator F.

Mounted on the cover l6 of water feeder B is a steam pressure gauge 39 and a pressure relief valve 450... A pipe 40a; leads from the relief valve to carry excess steam through the heater door plate 48 and exhaust it into the domestic heater.

Thev reliefv valve 40 is preferably of the weighted type so that it may be set to exhaust at certain pressures by merely adding or subtracting a weight such as two and one-half pounds in winter and one and one-half pounds in spring or early fall. The valve will relieve all excess steam whenever the pressure reaches the desired amount. Preferably the valve is designed to operate as accurately as possible to maintain a desired pressure and eliminate fluctuations on either side of the desired pressure. Tri-cocks 4! may be mounted on the body l5 at different levels for testing the water levels in the feeder.

A vacuum breaker is provided for the feeder B and comprises a pipe 42 connected to the body l5 at a point below the Water level therein. The pipe projects upwardly outside the feeder preferably fifteen feet or more and has its upper end open to the atmosphere. A column of water is carried in this pipe and any vacuum created in the water feeder will draw the water from the pipe, thus breaking the vacuum. It has been found in operation of the burner that when the flame goes out and the water feeder cools the steam in the feeder condenses creating a suction. The objectionable feature is that the suction draws oil through the steam nozzle to clog the water feeder. Hence, if the vacuum in thefeeder is not permitted to rise high enough no oil can be drawn through the steam nozzle.

The ignition chamber C, Figs. 1 and 4, for the burner nozzle comprises a cylindrical body 45 positioned beyond the Water feeder B and secured to the base plate A preferably by welding. One end of the chamber C is closed by a detachable cover plate 41 carrying the steam and fuel nozzle housings D and provided with holes through which the steam and oil supply pipes project. The other end of the housing C is closed by the heater door plate 48 which takes the place of the door of the domestic heater H. An opening 49 is provided in the door plate 48 to allow passage of the frame therethrough from the burner nozzle. The housing C is further provided with a lighting port normally closed by a cover 50.

A starting oil pan 5| is provided in the bottom of the housing C for receiving oil dripping from the burner nozzle. The oil pan 5| is partially filled with oil and provided with a braided asbestos wick which may be lighted to provide a starting flame for the'burner. An overflow pipe 10 leads from the side of the oil pan 5| intermediate the top and bottom thereof to carry off surplus oil to the safety valve unit G to be later described.

Opening into one side of the housing C is a draft turmel or flue 52 which may be lined with felt to muffle combustion noise.

A steam nozzle 55 and oil nozzle 56 are secured to the nozzle housing D. The steam nozzle 55 comprises a pipe having an extending lower lip onto which the oil nozzle 56 is adapted to drop oil. The steam nozzle is positioned centrally of opening 49 in door plate 48 to direct the flame through combustion chamber E into the heater H.

The combustion chamber E (Fig. 1) is a 1ongitudinal passage which confines the burning gases and directs them onto the steam generator F. The combustion chamber as shown is separated from the housing C by the heater door plate 48 and its interior is preferably lined with a refractory material 51. At the rear end of the combustion chamber is mounted the steam generator F.

The steam generator F, (Figs. 1 and 5) consists of a water leg 60 of rectangular cross-section disposed centrally across the rear end of the combustion chamber E. The lower end of the water leg 60 is connected to water pipe |9 leading from the water feeder B and is supplied with water therefrom. Surmounting the water leg 60 is a steam chamber 6| into which steam rises. Preferably the steam chamber 6| is partly exposed to the flame in the combustion chamber to superheat the steam therein and thus insure the dry steam essential for proper combustion.

Leading from the upper side of the steam chamber 6| through the heater door plate 48 and connected to the water feeder B is a pipe 62. In this manner the steam pressures in the steam chamber 6| and water feeder B are equalized.

upon the oil consumption of the burner.

Steam is supplied to the steam nozzle 55 by means of a pipe 63 leading from the pipe 62. Preferably the pipe 62 is arranged so that it slopes from steam chamber 6| to the water feeder B and the steam pipe 63 is carried upwardly before descending to the steam nozzle, thus tending to prevent any condensate from passing back to the steam chamber 6| or entering the steam pipe 63.

Fuel, such as oil, is supplied to the nozzle 56 through pipe 65 as previously described. The supply of oil is thermostatically controlled, as shown in Fig. 2, by a valve 66 mounted on the pipe 65 and controlled by a lever 61 connected by a chain 68 to the thermostat T. The thermostat may be of any suitable type but is preferably one that regulates gradually through a narrow range without sudden change. A sediment trap (not shown) may be interposed in the pipe 65 to insure the delivery of oil free from impurities to the burner nozzle.

The safety trip valve unit G operates to shut off the fuel supply, if for any reason the burner has failed to operate. The outlet pipe 10 is connected to oil pan 5| into which unconsumed oil flows from the oil nozzle and overflows into said outlet pipe Hi which opens downwardly into an oil trip pan 1|. Preferably outlet pipe ll] is goosenecked to prevent any flames passing therethrough into the oil trip pan H and igniting the oil therein.

The oil trip pan H is mounted on a pan holder 12 which depends from one end of a lever 13. The lever 13 is balanced on a yoke 15 extending upwardly from the base A and has a counterweight M on its opposite end. An ear 16 is provided at the pan end of the lever 13 and engages a latch 11 which is tiltable and carries a weight 18. Connected to the latch 11 and. rotatable thereby is the stem 19 of a valve 80 which is mounted on the fuel pipe 65 at a point beyond the valve 66. When sufficient oil overflows into oil drip pan 1| the lever 13 is unbalanced, latch 11 is disengaged and turns valve stem 19 which operates to close valve 80 and shut oif the oil supply.

The burner is preferably operated in the following manner:

The fire is started by lighting the asbestos wick in the oil pan 5| and steam is quickly generated. The steam passes to the steam nozzle 55 adjacent the oil nozzle 56 where it atomizes the oil dropping therefrom and the atomized mixture is ignited by the flame in the oil pan.

The flame is directed through the combustion chamber E by the steam jet and the induced draft to the steam generator F. In passing into the fire box of the domestic furnace the flame heats the air of a hot air system or the water in a hot water or steam system. The steam generated in the generator F is carried around to the steam nozzle 55 where it atomizes the oil thereby completing the cycle.

The principle on which the burner operates is that the water delivered to the steam generator is kept at a constant level by the float controlled valve in the water feeder and the steam delivered to the steam atomizer is kept at an unusually low pressure by the relief valve. The amount of steam pressure normally maintained depends In a burner such as that shown in the drawings having an oil consumption range from one-sixth to two gallons per hour the relief valve is set at one or one and one-half pounds at the lower rate of consumption and at two and one-half or three pounds at the higher rate. On larger installations, such as apartment houses or hotels where larger quantities of oil are burned per hour a higher constant pressure up to say five pounds will naturally be required. It is desired to operate on as low a steam pressure as will atomize the oil properly and keep the burner and heater clean.

The amount of oil delivered to the nozzle and consequently the heat produced is controlled by the thermostat operating the valve in the fuel pipe. The amount of air necessary for eificient combustion is automatically provided at all times by the natural induction effect of the steam jet and flame, which varies with the amount of fuel supplied.

There is thus no fluctuation in the steam pressure which heretofore has ranged from 1 to 15 lbs. and which was continually blowing out the flame at higher pressures when a small amount of fuel was being consumed and which was so difficult to control. With the unusually low constant steam pressure disclosed herein this difficulty is eliminated and adequate heat to maintain a desired house temperature is available at all times.

The fuel supply by this method is not turned on and then completely ofi as in other methods. The burner is operated continually but the oil consumption is not greater than in other burners for the reason that the heat requirements are maintained by burning the minimum amount of oil rather than by burning an excessive amount part of the time and then shutting the burner ofl completely. The low steam pressure used does not create the objectionable combustion noise so apparent in burners operated by other methods and using higher steam pressures. Hence, all the objects of the invention have been accomplished.

What is claimed is, I

1. The method of burning liquid fuel and controlling combustion thereof, which comprises supplying the fuel to an atomizing device, supplying steam under low pressure to said device and utilizing said steam to atomize the fuel, supplying air for combustion by the inductive action of the atomizing device, burning the mixture of air, fuel and steam, maintaining said low steam pressure substantially constant, and varying the heating capacity of the burning mixture by varying only the supply of fuel.

2. The method of burning liquid fuel and controlling combustion thereof, which comprises supplying the fuel to an atomizing device, supplying steam under low pressure to said device and utilizing said steam to atomize the fuel, supplying air for combustion by the inductive action of the atomizing device, burning the mixture of air, fuel and steam, and varying the heating capacity of the burning mixture by varying only the supply of fuel. JOHN J. HARMAN. 

